Apparatus for liquefying air.



No. 895,192. 7' i PATESTED AUG. 4, 1908. J. F. PLACE. j; APPARATUS FOR LIQUEPYING' AIR.

v v APPLICATION FILED AUG. 24, 1005. 6 EHELTS SHFET 1 f I 7 {\IUCHtOZ 3M4 P XTENTED 'UG. 4 1908. N0. 5,192. J.- F. PLACE- vn APPARATUS FOR LIQUEFYING AIR.

APPLICATION FILED 1.110.24. 1906.

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LP. PLACE. APPARATUS FOR LIQUEFYING AIR.

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PATENTED AUGA, 190s.

J. P. PLACE. APPARATUS FOR LIQUEFYING'AIR.

APPLICATION FILED AUG.24,1906.

6 SHEETS-SHEET 4 Z .w m U 4 3 No. 895,192. J F PLACE PATENTED AUG. 4, 190a. APPARATUS FOR LIQUEFYING AIR.

APPLICATION FILED AUG.2 1906.

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APPLICATION TILED AUG. 24, 1906.

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T all whom it may concern:

I we". run STATES PATENT. OFFICE.

JAMES F. PLACE, OF GLENRIDGE, NEW JERSEY, ASSIGNOR TO AMERICAN AIR LIQUEFYING CO., A CORPORATION OF .IEW YORK.

. APPARATUS FOR moonrvnvo AIR.

Specification of Letters Patent.

Patented Aug. 4. 19.08.

Application filed August 24, 1906. Serial in). 381,918.

Be it known that I, JAMES F. PLACE, a citizen of the United Statesand a resident of Glenridge, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Apparatus for Liquefying Air, of which the following is a s ecification.

his invention relates to im rovements in mechanism or apparatus for iquefying atmospheric air. t is equally as applicable to hqucfymg any other gases or gaseous mixtures.

My system also invo ves partial se &.d.

' tron, or fractional distillation as wel as liquefaction.

The object of the invention is to produce liquid air at a less cost thanaherctofore, so that it and its constituent gases, ox *gen and nitrogen, may be used commercial y in the arts and industries. This object I attain in the manner and by the mechanism hereinafter described, reference being liati ito the accompanying drawings, in wh1eh Figure 1 is a general view, partly in vertical section, of the mechanism I employ for compressing, cooling and drying the air, preparatory toiiquefaction. Fig. 2 is an end view of my expansion engine, and a view of the counter-current interchanger in transverse vertical section. Fig. 3 IS a longitu dinal vertical section of my insulatedair expansion engine, showing in detail the various parts. Fig. 4 is a longitudinal vertical sec tion of my improved liquefier, and highpressure interchanger. Fig. f5 is a modification in construction of my improved liqueiicr, showing in vertical section the preferred construction thereof. Fig. 6 is a modified form in vertical section of the li'quefier shown in Fig. 4. Both the forms of liquefier shown in Figs. 5 and 6, are adapted for use with the pipes and connections shown in Fig. 4. Fig. 7 is a transverse vertical section of the engine cylinder and valve chamber, through the line a a on Fig. 3. Figs. 8 and 9 are sootional views showing, the shoes or slippers of wood or other suitable material to take the weight of valve and avoid friction, the latter being a transverse section of valve on the line 0 c of Fig. 3.

Similar reference 'marks refer to similar parts throughout the several drawings.

In Fig. 1, I show at l the main air eumprefisor by which I propose to compress the passed thence through the pipe 3 into the'=.

calcium chlorid drum 4, where it passes up through the several baskets 5, and is brought in contactwith charges of calcium chlorid 6. This process absorbs considerable of the moisture in the compressed air. From here the air is passed through the pipe 7 into the caustic potash drum 8, and is brought in contact with the caustic potash charges 9, in a similar manner as in the drum 4. This caustic potash removes more of the moisture, and absorbs all of the carbonic acid gas (C0,) in the air, so that as it passes into pipe 9, it may be considered practically dry. I have At 2-is Shawna-ii run an air expansion engine continuously--- with air subjected tothe treatment of passint, through calcium ehlorid and caustic potash in this manner without further drymg, and never experienced any trouble from frost. The air usually showed by the hygrometer but about 13% saturation, which at a pressure of 180 lbs. is very small. From pipe 9 the air (passes into the counter-current mt-erchanger ee Fig. 2).

This interchanger is" preferably made in the following manner:

The pipe 9 delivers to the three smailer helical copper tubes 10, which pass down the insulated drum 11, and then deliver to the transverse pipe 12, which connects with the helical coil 13 in the insulated drum 14, and thence through the transverse pipe 15 to the helical coil 16 in the insulated drum 17. The coils have in the center-of each the deadair drums 18, 19 and 20, respective] ;so that the three tubes forming the helica coils 1O, 13 and 16 respectively, lust till the space left in the drums 11, 14 and 17, leaving the helical passages 21, 22 and 23, which carry back the exhaust and ex anded air from the engine, and which wi l he referred to later on. The compressed air as it leaves the helical coil 16 (Fig. 2) passes into the ipe 24 and through the passage 25 around t e engine 32 (see Figs. 3 and 7), to the valve chamber 26;

Here it passes inside the main valve (68) through the oblong apertures 27, when it is delivered to the engine through the ports 28 or 28, and cut oil at such portion of the stroke as desired by the cut-oli' valves 29 and 29. j

The expansion engine 32 consists of )referably the iron cylinder and cylindrical valve M inn-wuss: Wa -um. .w. me

.ing inside of same.

'mounted with bronze 93.

chamber as shown, the cylinder being lined with a bushing 69, of steel or other suitable metal; in this way the annular port 25 (see Fig. 7) around the cylinder to the valve chamber, is formed. As for the iston, I make the interior (collars 71 and 71) of bronze, and cover or int-lose the same with the parts 72 and 72 and 73, made of wood or fiber or some other suitable non-conduci ing material, held together by the bolts 74. packings 75 are preferably of leather.

The valve 68 is preferably made of cast iron or bronze-aluminum alloy of the balanced piston type without expansion rings, and with the cut-off valves 29 and 229' operat- To reduce friction, I use slippers or shoes 101 and 101' which take the weight of valve (see Figs. 8 and 9). These slippers are made referably of stri s of closegrained hard woo or any other suitable nonconducting material which can be used without lubrication and will run with minimum friction. The long annular ports 28 and 28 enable me to use the inner edges 76, 76 for cutting off, and in this way the main valve and cut-off valvesmove at all times in opposite directions, thus insuring a sharp cut-off without throttling, which is very essential in an air expansion engine. The exhaust is over the ends of the main valve into the chambers 100 at each end and 100' below the valve chamber, which connects with and delivers to the conduit 61.

The piston rod 77 is preferably made. of steel, is very long as shown, so as to retard the conduction of heat from the outside throu h the same; and is insulated by the long s eeve 78 made of wood or fiber or some other material of low thermal conductivity, which is preferably reinforced by steel rings or ferrules 84 andSS, and the jam nuts 86 and 87, which are of wood or fiber reinforced by the metal mountings 88 and S8. The outer ring or ferrule 84, carries the stuffing box 80.

.Which is made of wood or fiber covered with bronze 90. The gland 91 and cap 92 are preferably made of wood, the latter being The piston rod insulating sleeve 78, passes through the insulations 111 against circumamhient heat which envelop the engine, as slzown in Fig. 3.

The stem 94 of the main valve is preferably of steel, very long as shown; and is made tubular, so as to carry in and through the same the cut-olf stem 95. An insulating sleeve 96 incloses these valve stems and passes through the ins'ulations 111 of the engine. On its outer end it carries a stuffing box 08, ii'hiclris' made of nonconducting material, same as the sleeve. The outer end of the main valve stem 94 also carries a. stulling box DEL-around the cut-off stem (95), preferably made of steel.

The engine is supported by the main slibs or walls, partitions or end frames, 103 and 103, which are preferably made of hard The wood or fiber, or other suitable material of low thermal conductivity, which are made fast as shown, to the iron bed (100) of engine. To the enginecylinder ends are bolted similar; non-conducting plank ends 104and 104'. which are reinforced by the-Router.- plank ends 105 and 105 ofsimilarnon-conducting ma-, terial. Through the plank ends 104 and 104{ are passed ."rbcr tubes or hollow beams 106,\ which are inclosed by other similar tubes or hollow beams 107, the ends of which are forced against the sides of the structnralt frame, 103 and 103' and 10-1 and 104'; eight l long steel rods or bolts 108, are assedf through the non-conducting hollow earns 106, which firmly hold the plank frame support-s 103 and 103' to the iron bed frame 109 0y the nuts 110. It will be seen the engine is virtually suspended on thenon-conducting hollow beams 106 by meanslof the side or plank ends 104 and 104thus being thoroughly insulated from all contact with the iron frame or bed; this insulation being further reinforced by the non-conducting frame 103 and 103, and the insulation of the .bolts within the inner and outer hollow beams 106 and 107. The engine is then thoroughly insulated from the ciroumambient heat by" the wool packing 111, completely en eloping the engine and the parts wherein the 8.11 is Q delivered to and from the same and expanded therein.

' At 102 (see Fig. 3) I have a thin paper or canvas or other suitable partition, or inclusure fastened to and around the edges of the plank ends 104 and 104', and which passes all around the expansion engine, and to which is lucd a covering of nickel foil or silver foil, having on the outer surface a high mirror-like polish. The outer flat surface of the non-conducting plank ends 104 and 104 and 105 and 105, are also covered with this highly polished nickel or silver foil. This polished partition or surface which completely surrounds the engine, serves to de- 110 fleet outside radiant heat from the engine. Within this polished inclosure (102) I have the space filled with cider down or hares fur (112) or other suitable packings of relatively very low thermal conductivity. 4

While I can liquefy a portion of the air expanded in the engine cy indcr, I find it more advantageous to have a separate liquefier,

and to use therein air compressed to a considerably higher tension. In this way Icompress to from 40 to 15 atmospheres theair used in the liqueiicror to a compression above the critical pressure, which is about 39 atmospheres. It is a waste of energy in liquefying air to compress above about -15 atmospheres, for no amount of compression above the critical pressure (not even 1,000, atmospheres) will of itself produce liquefaction. A necessary condition precedentto liquefaction is a temperature at or below the 30 critical temperature, 220 F. Another advantage of a separate liquefier, is the fact that the temperature of the air used in the engine does not have to be carried so low,

and thus a lower initial temperature and lower initial pressure may be used, and a greater percentage. of power is recoverc d from the air expanded. Besides, in using a separate liquefier all of the compressed air delivered to the liquefier may be liquefied; while in an expansion engine cylinder only about of the air expanded can he liquefied under the most favorable conditions.

To recur to Fig. l, at I show a feed pipe supplied with compressed air at the same tension as used in the expansion engine and which is delivered to the high-tension air compressor (33), through the throttle. valve 31. Air is taken at say 180 lbs. gage, and is compressed in the compressor 33 to about 45 atmospheres, or say 650 lbs. The heat of compression is then removed in the water cooler 34. At 35 I show a CO, compressor, with condenser 36, expansion valve 37 and expansion pipe 38 and coil 39, all of the ordinary type, except that I have arranged the pipe 38 and coil 39, in an original and novel manner, so as to get the best results in cooling of and freezing out the remaining moisture in the compressed air. The C0,. liquid vaporizing or expansion pipe 38, I locate in an insulating casing or conduit 40, which is made of wood or paper or some other material of low thermal conductivity. The pipe 38 connects with the helical coil 39 at the bottom, which fills the remaining space in the drum 41, and thus forms the. helical air passage 42. It will be seen that the highly compressed air as it leaves the cooler 34 passes thrc ugh the pipe 43 into this helical passage 42, and down the same around the coil 13!) in counter-current to the vaporizing CO liquid therein, and thence enters the casing or conduit and passes upwardly, still in counter current to the vaporizing CO, liquid in the pipe 38. Any remaining moisture in the compressed air is thus frozen out and deposited as frost on the coils 39 and pipe 38, from which it can be melted by stopping the CO, compressor 35, and openingvalve 44, and the water drained oil through drain-pipe 45 on opening the cock 46. The discharge pipe 47 connects with the inlet pipe 47' to the liquciier,(shownin Fig. 4). The air ol'high-tension, now thoroughly dry and free from CO gas, now enters the liquefier shown in Fig. 4, and passes up through the helical copper oils 48 around the dead air drum 49 into the ropetwisted copper pipe 50, which forms apart of the liquetier, where it is ready for liquefaction, (see Figs. 4, 5 and 6). The lower end of this liquefying pipe 50 has a liquid releasing valve 51. operated by the nonconducting stem 52 and the hand wheel 53. in th preferred construction (shown in Fig. 5), I show the pipe 50 having at the end a suitably enlarged portion (54) to act as a holding reservoir, or condenser, which is suhiiierged in,

,insulated by the vacuum 56, any heat of evaporation supplied to the liquid air in the holder (55) must be drawn from the hightension air in the pipe 50 and 54, the latter being submerged therein. This high tension air will liquefy at its critical temperature -220 F., whereas the liquefied air in the holder 55, being released to atmospheric pressure, is at a constant temperature of 3l3,

or 93 degrees colder, thus insuring rapid withdrawal of heat from the highly c0mpressed air in the submerged condenser 54.

All vapor from the liquid air evaporatedin holder 55. is conserved as it passes up through the mouth of the holder 55, at 57, around, over and along the pipe 50, through the expanded air conduit 58, and its helical continuation of passage 59, and the connecting passage 60, and thence into the low-pressure or expanded air helical passages .23, 22 and 21 of the interchanger, successively, (see Figs. 2 and 4).

At 61 (see Figs. 3,4, 5 and 6) I show the.

exhaust or expanded and cold air conduit from the insulated expansion engine. This conduit is so arranged that it delivers first the cold expanded exhaust air from the engine to the liquefier-prefcrahly to the pipe 50, above the liquid air holder as shown in Fig. 5. 5) it mixes with the cold vapor from the evaporating liquid air in the holder '55-, and passes up the conduit 58 into the expanded air passage 59, 23, 2'2 and 21, over first the liquciier high tension feed pipe 50 and highpressure supply coil 48 of the liquetier and thence into the interchanger over the engine feed pipcor coils 16, 13, 1'2, and lOsucccssively, and in counter-current thereto.

My exhaust or lmv-pressure conduit or passage. 58, 59, 23, 22, and .21 of the countereurrent interchanger (see Figs. 2 and 4) is used in common for cooling both the com pressed air of high tension in the liquetier pipe 50, and coil 59: and the compressed air of less tension supplied to the engine. in the coils 10, 13, and 16. This low-pressure or continuous conduit 58, 59, 23, 22, and 21 leaves the interchanger at 116 (see Fig. 2) and connects, if desired, with the suction of the. main air-compressor (1) at 116 (see Fi 1). With the valve 117 closed and the valve 118 open the return flow of air from the engine exhaust conduit 61, and that which is vaporized from liquefied air inholder 55 or 55 (see Figs. 5 and 6) will he deliveredto the compressor 1 and he re-compressed; but with There, in passage 58 (see Figs. 4 and valve 117 open and valve 118 closed, the com ressor will constantly take in all new air tnrough the inlet 119, and the return flow will be discharged outside4hg apparatus through the valve 117. W 120' are for the discharge of brine from the calcium chlorid drum 4, and the caustic potash drum 8, respectively.

At 62 I show a vacuum-jacketedliquid-air reservoir, with siphondischarge (63) operated by the cock 64, and the inlet valve 65. In the construction shown in Fig. 5, this tank 62 takes the overflow from the holder 55. The holder 55 is also provided with a siphon discharge 66 and insulated valve 67, located at a suitable distance above the bot- .tom, so that a quantity of liquid will at all times remain in the holder. On closing the valve 65 and opening valve 64 (see Figs. 4 and 6) compressed air from pipe 47 may be admitted to the top of reservoir 62 through the pipe 121 by opening cock 122, and force out any liquid therein through the siphon 63.

In Fig. 6, a modified form of holder 55 (referred to here as 55) is shown located within the )assage or conduit 58, the overflow liquid air t herefrom being delivered to said conduit, from which it is collected in the reservoir 62. At 113 I show a small valve, connecting the high-pressure air in the valve .chamber '26 with the exhaust chamber 100', and arranged to open or close by the non-conducting stem 114 which )asses through the insulmions 1 11 and 1 2, w iereby the high pressure air which may be liquefied in the port 25, or chamber '26, may be drained out into the exhaust chamber 100'; from thence, it may be drawn from the exhaust chamber by the low-pressure non-conducting liquid discharge pipe. 1 15.

My improved cut-off valve (68) herein shown is especially adapted to a reciprocating air-expansion en ine. It has been shown and described in detail only in order to more clearly explain my improved air-liquefying a aratus; no claim is made to the patentalile features of said valve, as it is my purpose to file a se aratc application therefor.

No attempt as been made in the accompanying drawings to show the proper proportions of the pipes, conduits, orother parts; but only to show such parts of the invention relative to each other, so that the o aeration of the mechanism Inuy be easily understood by one skilled in the art.

Power from an outside source may be supplied to the several compressors, by bolts to wheels 80, 81, and 82 respectively; and the )ower of the expansion engine may be utilized by belting on to a counter-shaft (not here shown) and connecting same by belt with one of the air compressors.

It will be seen that 1 do not dc )tlltl entirely upon the cold exhaust from the engin to 55 continuously produce liquefaction of the air,

above its critical The cocks 120 and" but only in starting rip. By having the air in the liquefier 50 or 54 at a tension at or ressu e (which is about 39 atmospheres), then the air therein liquefies at or below its critical tem erature, -220 F.; and after the ex antle air exhausted fromthe e ine (un er the cumulative refrigerative effect of coolin lower and lower the incoming supply of com ressed air thereto by the exhaust there rom) has dropped to below '220 F., then the highpressure air in coils 48 and pipe 50 commences to licuefy, and the liquid in pi e 50 falls by gravity to the lower end therco and into the condenser 54 (see Fig. 5). hen this condenser (or the liquefyin pipe 50- see Fig. 6) is full, the liquid air tdierein may be discharged to the eva orating holder 55 or 55'. As this holder ecomes filled the liquid air therein at substantially atmosheric pressure, evaporates rapidly and draws its latent heat of vaporization from the cooled com ressed air in the now submerged condenser 50 or 54). Herein lies the great value of my system. for this latent heat reuired for va orization (of the low-pressure liquid in the liolder 55 or 55) is now about 120 B. t. u, 'per pound whereas the latent heat of com ensation given out by the air cooled to 220 F. and at 40 atmospheres compression, in the submerged condenser, is at zero or nil. air in the submerged sir li uefying condenser, )asses readily and mpid iy from a gas to a liquid as fast as cooled to -220 F.-with out the. evolution of any heat to neutralize refrigeration, and without reduction of pressure in the condenser. The liquid may then be sub-cooled to -313 F. before discharging it into the insulated evaporatingholder 55, through the liquid-sir discharging 0r pressure-releasing valve 51; so that when.dis charged through said valve to said holder or evaporating reservoir, no vaporization is required to reduce its temperature to the tem erature of the low-pressure liquid air in said iolder. All the vapor evaporated from the liquid in said holder is utilized-1st, to cool the su )ply of high-pressure air delivered to the sulnnerged condenser in feed pi es 48 and 50; and 2nd, to cool the supply o f compressed air delivered to the engine in pipes 16, 13 and 10.

It will be found by a computation of the refrigerative effect produced, that once the system is properly cooled by the expanded Therefore the high-pressure I exhaust an from the engine, and the low- )IQSSUIO liquid-air evaporating holder 55 is 'ully charged with liquid air produced thereby, from the high-pressure condenser, then every ound of liquid thereafter evaporated in suit holder at substantially atmospheric pressure, will produce fully two pounds of' liquid airin the highpressure submerged "condenser 54, (so long as said condenser is kept supplied with air compressed to 40 or more atmospheres) and without requiring any refrigerating help from the eng1ne;-the

output oflthe liquefier when cooled and charged and operated alone, or amount of liquid air drawn from the apparatus through the siphon discharge tube 66, being equal to that vaporized in the insulated holder 55, or about of all the air supplied to the liquefier. In fact, continuous running of the engine thereafter is more a matter of economy or capacity of the apparatus for the production of liquid air, than for refrigerative ell'ect.

Wherever the words insulation, insulated or insulating occur herein, they refer to insulation of the parts against the inflow thereto of circumambient heat. The word engine as used herein, refers to the expansion c'linder, valves, etc., as shown in Fig. 3, am not to the crank,bed, etc.,unless so s )ecially specified.

The features of my invention shown in Figs, 3, 7, 8 and 9, re ating t0 the details of my improved insulated refrigerating engine for producing low temperatures, which I use in combination with my improved submerged liquefier and counter-current system as herein shown and described, I reserve for a future application for a patent thereon.

Having thus described my invention, what I claim as new and original and desire to secure by Letters Patent, is- 1. In an air liquefving apparatus the combination of an insu ated expansion engine,

a high pressure liquefier, and a double '-countercurrent interchanger having two separate high pressure conduits and a lowpressure cold air exhaust conduit common to both; one of said high-pressure conduits delivering to said engine and the other to said liquefier; and means for supplying compressed air for expanding in the engine to the first and compressed air of considerably higher tension to the other.

2. An air liquefying apparatus, comprising an expansion engine and a liquefierboth insulated against circumambient heat-each having a feed pipe connected therewith; an exhaust condult from said engine, arranged to pass the cold exhaust air therefrom over both of said feed pipes; and means for sup plying compressor air tosaid engine feed pipe and compressed air of a higher tension to said liquefier feed pipe.

3. An air liquefying apparatus, comprising an expansion engine and a hquetfier, each having a feed pipe connected therewith; an exhaust conduit from said engine, arranged so as to pass the cold expanded air therefrom sucessiv'ely over first the liquetier and then the engine feed pipes; and means for supplying compressed air to said en ine feed pipe,

and compressed air of a higlier tension to said liquefier feed pipe.

4. Air-liquefying mechanism comprising sure compressed air feed pipe, provided with a liquid air releasing valve at its lower end inclosed by a low-pressure liquid-air evaporatingholderopen at its upper end the parts being so arranged that when in operation the cold expanded air exhausted from the engine is conducted over the outside of said liquefier compressed air feed pipe, and that the lower end of said pipe is sulnnera ed in the low pressure liquid air in said he der.

5. Mechanism for liquefying atmospheric air, comprising in operative combination, a liquid air holder or evaporating receptacle, arranged to be charged with liquid air of low pressure; a high-pressure liquefier located within said liquid air receptacle, and having a compressed air supply pipe; and an air expanding engine,.arranged to pass the cold expanded air exhausted therefrom, over said supply pi e.

6. Mec ianism for li uefying atmospheric air, comprising a liquiil air holder or receptacle, arranged to be charged with liquid air of low pressure; a high-pressure hquefier located within said liquid air receptacle, and having a compressed air supply pipe; and an air expanding engine, arranged to pass the cold expanded air exhausted therefrom, over said supply pipe; in combination wit-h means for supplying compressed air to said engine, and compressed air of higher tension to said liquefier.

7. An apparatus for liquefying atmospheric air, comprising an air-expanding enine having an msulated ex'haust conduit; 9.

ow-pressure liquid air receptacle or holder opening to said conduit; and a hquefier within said holder, having a high-pressure compressed air supply pipesaid i ue'fier being arranged to be submerged 1n the ow-pressure. liquid air in said holder.

8. An apparatus for c'fying atmospheric air, comprising a lug -pressure liqueiier; and an air-expanding engine arranged to conduct the cold expanded air exhausted therefrom to and over said hquetier; and

means for supplying to said liquetier compressed air atv or above substantially its critical pressure, and to said engine compressed air at considerably less pressure.

9. Air-litmefying mechanism comprising in operativecombination, an air-expanding engine having an expanded air exhaust conduit; and a liquefiereach having dlstinct compressed air feed pipes; said hqueher consisting of a pipe or pipes arranged to be supplied with compressed air at one end and having a liquid-air releasing valve at the other or lower end, inclosed by a low-pres sure liquid-air evaporating receptacle c' nected with said engine exhaust conduitthe parts being so arranged that the lower end of said liquefier pipe is submerged in the inclos'ed bv a low-pressure liquid-air evaporatin holder 0 Jen at itsupper end and connecte with sai engine exhaust or expanded air conduit;the parts being so arranged that when' in operation only liquid air can pass through said valve, and that the lower end of said liquefier high-pressure feed pi e is constantly submerged in the liquid air released from'pressure and delivered to said holder through said valve; and that as said li uid air or portions thereof evaporate in said holder the vapor therefrom passes over .said lixiefier high-pressure feed pipe.

11. n apparatus for lique'fying atmospheric an, comprising in operative combination, an air-expansion engine, arranged to expand compressed air against resistance therein; a counter-current heat interchan er, arran ed to cool the compressed air supp ied to said engine by the expanded 'air exhausted therefrom; and a high pressure liquefier,-- the parts being'arranged to pass the expanded exhaust air from said engine, first over said liquefier and then through said interchanger.

12. An apparatus for liquefying atmospheric air, comprising in operative combination, an air-expaudin engine; a low-pressure liquid air vessel or older; a law-pressure conduit. connected with said engine and with said holder; and a high-pressure pipe within said conduit, said high-pressure pipe havin .a high-pressure liquefier at one end locater within said liquid air holder.

- 13. An apparatus for liquefying atmospheric air, comprising in operative combination, an air-expansion engine; a low-pressure liquid air vessel or holder; a low-pressure conduit connected with said engine and with said holder; and a high-pressure pipe within said conduit, said high-pressure pipe having a high-pressure liquefier at one end located within said liquid air holder, and connected by a hqurdxhschargmg valve with said lowpressure holder.

14. Mechanism for liquefying atmospheric air, comprising inoperative combination, a liquid air holder or receptacle, arranged to he charged with liquid air of low pressure; a high-pressureliquefier having a compressed air supply p pe at one end and a liquid air discharging valve at its other end; and an air expanding engine, arranged to pass the cold expanded air exhausted therefrom, over said suppl pipe; said liquefier being arrangedto be an merged in the low-pressure liquid. air in said liquid air vessel.

15. An apparatus for li( uefying air, comrising a low-pressure liquid-air evaporating older; a hi h-pressure air-liquef mg con-- denser provided with a valved outl et for the withdrawal of liquefied air therefrom, to said 7 lowpressure holder, and arranged to be sub-- merged in a charge of low-pressure liquid air in said holder previously produced or liquefied at high-pressure in said condenser; in-

combination with an insulated air-expansion 39 with and delivering t ereto; said condenser being provided with .nieans for the withdrawal of liquefied air therefrom-the parts being arranged to pass said cold expanded air exhausted from the engine first over said condenser supply pipe and then through said interchanger.

17. An apparatus for liquefying atmospheric air, comprising in operative combination, an air liquefying high pressure eondenser, having a compressed-air supply pipe; said condenser being provided with means for the withdrawal of' liquefied air therefrom; and an insulated air-expansion engine having a compressed-air supply pipe,a1ul.ar-

ranged to pass the cold expanded air ex haustcd therefrom first over. said condenser supply pipe and then over said engine supply plpe.

18. An apparatus for liquefying atmos- 115 pheric air, comprising in operative combination, an air-liquefymg highrpressurc con denser, having a compressed-air supply pipe-said condenser being provided with means for the withdrawal of liquefied air therefrom; and an insulated air-expansion engine, arranged to pass the cold expanded air exhausted therefrom over said supply pipe; and means for supplying compressed air to said engine, and compressed air of lugher tension to said condenser.

19 An apparatus for liqu'efying atmos pheric air, comprising in operative COIl1blTl8. tion, an insulated air-expansion engine, having an exhaust conduit; a liquid air evaporating vessel, opening to said conduit; and an a1r-liquef ving condenser having a li uid-air dischargin valve at or near the ottom thereof de ivering to said vessel-said condenser being arranged to be submerged in low-pressure liquid air in said vessel which expanded-air conduit common to both and was previously produced or liquefied at a nmch higher tension in said condenser by the cold expanded air exhausted from said engine,

20. An apparatus for liquefying atmospheric air, compr sing'in operative eombina tion, an insulated air-expansion engine, having an exhaust conduit; a liquid air evaporating vessel, opening to said conduit; and an air-liquefying condenser having a liquidair discharging valve at or near the bottom thereof delivering to said vessel-said condenser being arranged to be submerged in low-pressure liquid air in said "essel which was previously produced or liquefied ata much higher tension in said condenser by the cold expanded air exhausted from said ongine: and means for supplying compressed air to said engine, and compressed air of higher tension to said condenser.

21. 'An apparatus for liquefying atmospheric air, comprising an air-expanding engine, having an insulated exhaust conduit; a

low-pressure liquid-air receptacle or contamer, opening to said conduit; an air-liqueiier within said receptacle, having a highpressure compressed-air supply pipe; and means for releasing the liquefied air from said liquefier to said container, and thereby submerging said liquctier, partially or com plctely, in low-pressure liquid air in said re- ('eptaclc.

22. in an apparatus for liquefying atmospheric air, the combination of an insulated air-expansion engine; an insulated low-pressure liquid-air evaporating vessel;- an. airliqucl';.-'ing condenser or liquclier within said vessel, having a high-pressure compressedair sup l v pipe; and means for conducting the cold expanded exhaust air from said engine to said liquetier high-pressure compressed-air supply pipe, and passing it back over the same;

23. An apparatus for liquefying air, comprising in operative combination, an insulated air-expanding engine; a compressedair-liquefving condenser; a double countcrcurrent thermal interchanger, consisting of two separate compressed-air conduits inclosed v an outwardly-(lelivering insulated arranged to receive the exhaust air from said cngine-ont of said compressed-airconduits delivering to said engine and the other to said condenser.

'24. An air-liquefying apparatus, comprising in operative combination an insulated air-expanding engine and a compressed-airliquefying condenser--each having a companded air therefrom outwardly and suc 7'0 cessively over first the said condenser feed pipe and then the said en inc feed pipe. 4

25. An apparatus for liquefying atmospheric air, comprising in operative combination, an insulated air-expansion engine; an insulated countercurrent thermal interchanger connected with and arranged to cool the compressed air supplied to said engine by the cold expanded air exhausted therefrom; an insulated low-pressure liquid-air evaporat- 0 ing vessel or holder connected with and delivering to said interchangcr; and ahigh pressure air-liquefying condenser within said holder, provided with means for withdrawin air therefrom after the liquefaction thereon 35 26. An apparatus for liquefying atmosphwic air, comprising in operative combination, an insulated air-expansion engine, hav-. ing an expanded air insulated exhaust (5011*. duit; an insulated 'iowpressure liquid-air 90. e\'aporating holder connected with said conduit a high-pressure air-liquef 'ing condenser within said holder, provided with means for discharging the liquefied air .t herein to said low-pressure holder; and a high-pressure conmrrssed-air supply pipe wi'hin said exhaust conduit, and connected with said air-liquefying condenser.

27. An apparatus for liquefying atmospheric air, comprising in operative combina tion, an insulated air-expansion engine, having an insulated expanded-air exhaust conduit; an insulated low-pressure liquid-air evaporating holder; a highpressure airliquefying condenser. provided with a. valved outlet for the withdrawal of liquefied air therefrom, and arranged to be submerged in the liquid air in said holder; and a highpressure compressed-air supply pipe, within said exhaust conduit, connected atits dcliv- 11o ery end with said condenser.

28. The combination in an air-liquefying apparatus, of an insulated liquid-air evaporating vessel or holder, arranged to be. charged with liquid air at substantially atniospheric pressure; .a high-pressure airliquefying condenser; 11 high-pressure compressed-air suppl pi )c, connected at its deliverv end with sair comlenscr-said condenser being arranged to be submerged in liq- 12o uid air of low-pressure previously liquefied at high pressure therein; and an insulated airexpansion engine, arranged to pass the cold expanded air exhausted therefrom outwardly over and along said compressed-air supply pipe; and a liquid air pressure-releaslng valve, connecting said lngh-pressure'condenser with said low-pressure liquid-air evaporating holder.

29. An apparatus for liquefying atmospheric air, comprising in operative combination, an insulated air-expansion engine; a counter-current thermal interchanger arranged to cool the compressed air supplied to said en ine by the expanded air exhausted therefrom: and an air-liquefying high-pressure liquefier, having means for the withdrawal ofliquefied air therefrom-the parts being arranged to pass said cold expanded exhaust air from the engine first over said liquefier, and then through said interchanger; and means for supplying compressed air to said engine, and compressed air of higher tension to said liquefier.

30. An apparatus for liquefying atmos pheric air, comprising in operative combination, an insulated air-expansion engine having a low-pressure expanded air conduit; a

. low-pressure liquid air evaporating .essel or holder opening to said conduit and a highpressure pipe within said conduit, said highpressure pipe having an air-liquefyin highpressure condenser at its lower end ocated within said liquid-air evaporating holder,

and having means tor the withdrawal of h ucfied an therefrom and dehvernu same i t a to said holder.

31. An apparatus for liquefying atmospheric air, comprising in operative combination, an insulated air-expansion engine, connected with a low-pressure expanded air conduit; a low-pressure liquid-air evaporating vessel or llOlt er, opening to said conduit; and a hi h-pressure pipe within said conduit,

said high-pressure pipe having an air-lique-. fyin high-pressure condenser at its lower end ocated within said liquid-air evapor'at ing holder, and having means for the withdrawal of liquefied air therefrom; and means for supplying compressed air to said engine, and compressed air of higher tension to said condenser.

32. In an apparatus for liqucfving atmos pheric air or other similar gases, the co1nl ination of means for compressing gas to and maintaining it at a relatively high pressure; and means for compressing other portions of gas to'a lower pressure and then ex anding the same, and means for utilizing tliis cold expanded gas to liquefy the said gas at the relatively high pressure.

An apparatus for liquefying atmospheric air, comprising in operative combination. an insulated air-expansion engine; a counter-current thermal interchanger; an exhaust conduit from said engine to said interchanger; an insulated liquid-air evaporating vessel or holder, openin to said conduit; and an .air-liquefyin'g high-pressure liquetier located within said liquid-air evaporating holder, having means for the withdrawal of liquefied air therefrom to said i holder; means for supplying compressed air haust conduit leading to said interc ranger;

and 'means for supplying said engine with compressed air of lesstension.

35. An ap aratus for liquefying air comprising a hig i-pressure liquefier, and means for supplying it with compressed air of relatively high tension; in combination with an insulated air-expanding engine, and means for supplying itwwith compressed air of less tension; and means for utilizing the exhaust air therefrom to cool the high tension airsupplied to said liquefier.

36 In an apparatus for liquefying atmospheric air, the combination of an airexpand ing engine and a liquefier, with means for supplying said engine and said liquefier with compressed air; means for utilizing the cold expanded air from said engine to liquef'y the compressed air being delivered to said liquetier; means for releasing therefrom the air in said liqueficr after liquefaction thereof; and means for retaining in contact with said liquefier the liquefied air released therefrom.

37. An apparatus for liquefying air, comprising a higlnpressure liquefier, and means for supplying it with air compressed to a relatively high tension; in combination with an air-expanding engine, and. means for supplying it with compressed air of less tension;

means for utilizing the cold exhaust air from said engine to liquefv the compressed air of relatively high tension being delivered to said liquefier; means for releasin therefrom the air in said liquefier after iiqucfaction thereof; and means for retaining in contact with said liquefier the liquefied air released therefrom.

Signed at Norwich in the county of New London and State of Connecticut this 22nd day of August A. D. 1906.

JAMES F. PLACE;

'itnesses:

CLARENCE -PLACE, JOHN A. INSLEE. 

